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Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/C/Firefox/services/settings/dumps/main/   (Firefox Browser Version 153.0.1©)  Datei vom 27.6.2026 mit Größe 28 kB image not shown  

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time_posix.cc


products/Sources/formale Sprachen/C/Firefox/ipc/chromium/src/base/time_posix.cc

// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/time.h" #ifdef XP_DARWIN # include #endif #include #if defined(ANDROID) && !defined(__LP64__) # include #else # include #endif #if defined(ANDROID) || defined(XP_UNIX) # include #endif #include #include #include "base/logging.h" namespace base { // The Time routines in this file use standard POSIX routines, or almost- // standard routines in the case of timegm. We need to use a Mach-specific // function for TimeTicks::Now() on Mac OS X. // Time ----------------------------------------------------------------------- // Some functions in time.cc use time_t directly, so we provide a zero offset // for them. The epoch is 1970-01-01 00:00:00 UTC. // static const int64_t Time::kTimeTToMicrosecondsOffset = GG_INT64_C(0); // static Time Time::Now() { struct timeval tv; struct timezone tz = {0, 0}; // UTC if (gettimeofday(&tv, &tz) != 0) { DCHECK(0) << "Could not determine time of day"; } // Combine seconds and microseconds in a 64-bit field containing microseconds // since the epoch. That's enough for nearly 600 centuries. return Time(tv.tv_sec * kMicrosecondsPerSecond + tv.tv_usec); } // static Time Time::NowFromSystemTime() { // Just use Now() because Now() returns the system time. return Now(); } // static Time Time::FromExploded(bool is_local, const Exploded& exploded) { struct tm timestruct; timestruct.tm_sec = exploded.second; timestruct.tm_min = exploded.minute; timestruct.tm_hour = exploded.hour; timestruct.tm_mday = exploded.day_of_month; timestruct.tm_mon = exploded.month - 1; timestruct.tm_year = exploded.year - 1900; timestruct.tm_wday = exploded.day_of_week; // mktime/timegm ignore this timestruct.tm_yday = 0; // mktime/timegm ignore this timestruct.tm_isdst = -1; // attempt to figure it out #ifndef XP_SOLARIS timestruct.tm_gmtoff = 0; // not a POSIX field, so mktime/timegm ignore timestruct.tm_zone = nullptr; // not a POSIX field, so mktime/timegm ignore #endif time_t seconds; #ifdef ANDROID seconds = mktime(×truct); #else if (is_local) seconds = mktime(×truct); else seconds = timegm(×truct); #endif int64_t milliseconds; // Handle overflow. Clamping the range to what mktime and timegm might // return is the best that can be done here. It's not ideal, but it's better // than failing here or ignoring the overflow case and treating each time // overflow as one second prior to the epoch. if (seconds == -1 && (exploded.year < 1969 || exploded.year > 1970)) { // If exploded.year is 1969 or 1970, take -1 as correct, with the // time indicating 1 second prior to the epoch. (1970 is allowed to handle // time zone and DST offsets.) Otherwise, return the most future or past // time representable. Assumes the time_t epoch is 1970-01-01 00:00:00 UTC. // // The minimum and maximum representible times that mktime and timegm could // return are used here instead of values outside that range to allow for // proper round-tripping between exploded and counter-type time // representations in the presence of possible truncation to time_t by // division and use with other functions that accept time_t. // // When representing the most distant time in the future, add in an extra // 999ms to avoid the time being less than any other possible value that // this function can return. // Take care to avoid overflows when time_t is int64_t. if (exploded.year < 1969) { int64_t min_seconds = (sizeof(time_t) < sizeof(int64_t)) ? std::numeric_limits::min() : std::numeric_limits::min(); milliseconds = min_seconds * kMillisecondsPerSecond; } else { int64_t max_seconds = (sizeof(time_t) < sizeof(int64_t)) ? std::numeric_limits::max() : std::numeric_limits::max(); milliseconds = max_seconds * kMillisecondsPerSecond; milliseconds += kMillisecondsPerSecond - 1; } } else { milliseconds = seconds * kMillisecondsPerSecond + exploded.millisecond; } return Time(milliseconds * kMicrosecondsPerMillisecond); } void Time::Explode(bool is_local, Exploded* exploded) const { // Time stores times with microsecond resolution, but Exploded only carries // millisecond resolution, so begin by being lossy. int64_t milliseconds = us_ / kMicrosecondsPerMillisecond; time_t seconds = milliseconds / kMillisecondsPerSecond; struct tm timestruct; if (is_local) localtime_r(&seconds, ×truct); else gmtime_r(&seconds, ×truct); exploded->year = timestruct.tm_year + 1900; exploded->month = timestruct.tm_mon + 1; exploded->day_of_week = timestruct.tm_wday; exploded->day_of_month = timestruct.tm_mday; exploded->hour = timestruct.tm_hour; exploded->minute = timestruct.tm_min; exploded->second = timestruct.tm_sec; exploded->millisecond = milliseconds % kMillisecondsPerSecond; } // TimeTicks ------------------------------------------------------------------ // static TimeTicks TimeTicks::Now() { uint64_t absolute_micro; #if defined(XP_DARWIN) static mach_timebase_info_data_t timebase_info; if (timebase_info.denom == 0) { // Zero-initialization of statics guarantees that denom will be 0 before // calling mach_timebase_info. mach_timebase_info will never set denom to // 0 as that would be invalid, so the zero-check can be used to determine // whether mach_timebase_info has already been called. This is // recommended by Apple's QA1398. kern_return_t kr = mach_timebase_info(&timebase_info); DCHECK(kr == KERN_SUCCESS); } // mach_absolute_time is it when it comes to ticks on the Mac. Other calls // with less precision (such as TickCount) just call through to // mach_absolute_time. // timebase_info converts absolute time tick units into nanoseconds. Convert // to microseconds up front to stave off overflows. absolute_micro = mach_absolute_time() / Time::kNanosecondsPerMicrosecond * timebase_info.numer / timebase_info.denom; // Don't bother with the rollover handling that the Windows version does. // With numer and denom = 1 (the expected case), the 64-bit absolute time // reported in nanoseconds is enough to last nearly 585 years. #elif defined(XP_OPENBSD) || defined(XP_UNIX) && \ defined(_POSIX_MONOTONIC_CLOCK) && \ _POSIX_MONOTONIC_CLOCK >= 0 struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) { NOTREACHED() << "clock_gettime(CLOCK_MONOTONIC) failed."; return TimeTicks(); } absolute_micro = (static_cast(ts.tv_sec) * Time::kMicrosecondsPerSecond) + (static_cast(ts.tv_nsec) / Time::kNanosecondsPerMicrosecond); #else // _POSIX_MONOTONIC_CLOCK # error No usable tick clock function on this platform. #endif // _POSIX_MONOTONIC_CLOCK return TimeTicks(absolute_micro); } } // namespace base

                                                                                                                                                                                                                                                                                                                                                                                                     

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